Electrolytic refining of metals



257, 1947. K. A. LlNDNER ET AL 21 9 ELECTROLYTIC REFINING 0F METALS Filed Jan. 50, 1942 8 Sheets-Sheet l llllllllllllllllllll i l I E i T INVENTORS:

, w/flmfl AMLz/gdner ATTORNEY May 2?, 19470 K. A. LINDNER ET AL 2,421,209

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, ATTORNEY K. A. ,LINDNER ET AL ELECTROLYTIC REFINING OF METALS a Sheets-Sheet s Filed Jan. 50, 1942 INVENTORS: 14% ay/$31300 1 1a BY 140$ fuse/7C 4 ATTORNEY May 27, 19 479 K. A. LINDNER ET AL ELECTROLYTIC REFINING 0F METALS May 27, 1947.

Filed Jan. 30, 1942 8 Sheets-Sheet 4 INJUL/ITM/V y 1947. K. A. LINDNER ET AL 2,421,209

ELECTRQLYTIC REFINING OF METALS Filed Jan. '50, 1942 8 Sheets-Sheet 5 INVENTORS: km) A. Lfnaner' May 27, 1947. K. A. LINDNER ET AL ELECTROLYTIC REFINING OF METALS Filed Jan. 50, 1942 8 Sheets-Sheet 6 INVENTO 5-. Karl A. Lin ngr' MMorr/wn p Buschz .5 1 7 7 ATTORNEY ay 27,1947. K. A. LINDNER ET AL 2,421,299

ELECTROLYTIC REFINING OF METALS 7 Filed Jan. 30, 1942 8 Sheets-Sheet '7 ATTORNEY May 27, 1947. i K. A. LlNbNER ET AL 2, 0

ELECTROLYTIC REFINING OF METALS Filed Jan. 30, 1942 a Sheets-Sheet 8 I T6 R13 Patented May 27, 1947 ZAZLZ ELECTROLYTIC BEFINING OF METALS Karl A. Lindner and William M. Morrison, Hainfield, and Adolph Busche, Stelton, N. 3., assignors to American smelting and Refining Company, New York, N. Y., a corporation of New Jersey Application January 30, 1942, Serial No. 428,820

larly adapted to the refining of copper, it is also applicable to the electrolytic refining of other metals.

Heretofore, in the production of electrolytic copper, by either the series or multiple system, it has been customary to suspend the electrodes in the electrolyte and maintain them in a fixed, stationary position during electrolysis. This arrangement does not permit the electrolysis to be carried out in a continuous manner. A large number of tanks or cells and auxiliary equipment is required which take up a great deal of floor space. More space is used than necessary due to the lack of precision methods for maintaining minimum spacing and accurate alignment of the electrodes. Further, in practicing prior electrolytic refining methods, much labor is needed to inspect, handle and align the electrodes. The temperature of the electrolyte also must be kept low enough to permit men to Work comfortably on top of the tanks. This is ordinarily below the temperature at which the electrolyte offers minimum resistance to the passage of electric current so that it is desirable to carry out the electrolysis at a higher temperature than that normally employed, in order to increase the current eniciency and efiect a saving in power.

The principal object of this invention is to overcome the disadvantages of the conventional electrolytic refining systems and provide a machine and method whereby electrolysis may be carried out continuously to produce electrolytically refined metal. To this end, we have devised an improved machine wherein the electrodes are electrically connected in series and continuously advanced along through the electrolyte while maintained in accurate spaced alignment. Electrolyte which is heated to a, high temperature is continuously circulated between the electrodes during electrolysis. The improved machine of this invention efiectively reduces the current leakage past the electrodes and attains a much higher current efficiency than has been possible in prior electrolytic processes. Our invention also provides for continuous removal of the anode slimes formed during electrolysis. By utilizing the present invention the precious metal values in the anode slimes can be recovered immediately without having to wait until the electrolysi is completed and the electrodes removed as is the conventional practice.

Another object of the present invention is to 12 Claims. (Cl. 204108) 2 provide an improved machine and method for electrolytically refining metals which is efficient, economical to operate, and wherein precision methods for maintaining proper spacing and alignment of the electrodes are employed.

Another object of this invention is to devise an electroprocessing machine for refining metals which is substantially automatic and operable to continuously deliver electrolytic metal and recover slimes.

Another object is to devise a machine which utilizes the series system of electrolytically refining metal wherein the current input is on the order of that used in the multiple system.

Another object is to provide a machine of the character described wherein electrodes of the impure metal to be refined are placed in a tank or cell containing electrolyte and moved continuously therethrough from a loading to an unloading station while electrolysis takes place.

Another object is to provide a continuously operable machine for producing electrolytically refined copper which includes mechanism for lifting groups of moving electrodes out of the electrolyte, as required for effecting inspection, correction of deposits, Washing, etc., while maintaining their relative position with respect to the remaining moving electrodes.

Another object is the provision of a machine for producing electrolytic metal which is capable of operating at much higher electrolyte temperatures and current densitie than heretofore-considered feasible.

Another object is to provide an improved electrolytic machine for refining metals having means operable in association with moving electrodes for gathering the slimes and efiecting their removal simultaneously while electrolysis is in progress.

Another object of the present invention is to devise an electrolytic machine for refining metals wherein provision is made for moving the electrodes through the electrolyt While the latter is heated to a high temperature and wherein a minimum clearance is maintained between the individual electrodes and between the electrodes and the tank or container for holding the electrolyte. -These provisions result in effecting a saving in labor and power and the current eniciency is markedly increased.

Still another object is to devise an improved process of electrolytically refining metals, such as copper, whereinthe electrodes of impure metal are continuously moved along through the electrolyte during electrolysis. This reduces the effeet of the anode and cathode polarization and permit-s the efiective use of higher current input values than would otherwise be feasible in electrolytic refining processes of this character.

These and other objects and advantages will become apparent as the description proceeds. One embodiment of the invention is illustrated in the accompanying drawings and described as applied to the series electrolytic refining of copper. It will be understood, however, that this is merely illustrative and not limitative of the scope of our invention. 7

In the drawings:

Figure 1 is a diagrammatic plan view of an electrolytic machine for refining copper built according to this invention, showing the general layout of the tanks, arrangement of the electrodes therein and electrical connections thereto;

Figure 2 is a similar plan view of a single tank, partly broken away, showing the electrode rack advancing screw mechanism, bus bars, and gutters for collecting slimes with their drain apertures;

Figure 3 is an end elevation of a tank illustrating the general shape of the inner walls and bottom of the tank and showing the drive mechanism for the electrode rack advancing screws;

Figure 4 is a more detailed plan view of a tank taken at the loading end showing the electrode racks in place, a portion of one rack being broken away to show certain structural features more clearly;

Figure 5 is a cross-sectional view taken on the line 55 of Figure 4 and looking in the direction of the arrows;

Figure 6 is a detail view of the electrode and supporting rack means taken on the line 6-6 of Figure 5 and looking in the direction of the arrows;

Figure '7 is a detail sectional view taken substantially on the line 1-1 of Figure 6 and looking in the direction of the arrows;

Figure 8 is a view similar to Figure 6 taken on the line 88 of Figure 5 and looking in the direction of the arrows;

Figure 9 is a detail sectional view taken substantially on the line 9-9 of Figure 8 and looking in the direction of the arrows;

Figure 10 is a detail perspective view of one of the electrode hangers;

Figure 11 is a similar perspective view, partly broken away, of an electrode;

Figures 12 and 13 are detail perspective views, respectively, of the movable clamping plate means arranged at one end on each rack and the fixed end plate member disposed at the opposite end, showing their associated electrical connecting means for making contact with a bus bar;

Figure 14 is a cross-sectional view taken through a tank, similarly as in Figure 5, showing an electrode rack, with electrodes omitted, equipped with a slime removing attachment for sweeping the settled solids into side gutters for collection and removal;

Figure 15 is a plan view of the slime rack;

Figure 16 is a side elevational view of the same;

Figure 17 is a sectional view taken on the line 11-11 of Figure 15 and looking in the direction of the arrows:

Figure 18 is a front elevation of the traveling hydraulic crane for lifting and transferring racks of electrodes, the tank being shown in cross-section and the crane having part of the framework broken away and illustrated in position for raising a rack out of the tank;

General construction The electrolytic processing machine of this invention, in general, comprises one or more tanks for holding electrolyte through which is moved electrodes formed of the impure metal to be electrolytically refined. The electrodes are assembled in racks and, during electrolysis, maintained accurately spaced and electrically insulated from each other by dielectric material. Multiple racks of electrodes are supported on conveyor means and moved as a unit at a predetermined rate of speed from one end of the tank to the other.

During this continuous movement direct current is simultaneously conducted from one electrode to the next through the electrolyte to effect electrolysis. A traveling crane is operatively associated therewith to provide suitable mechanism for removing and replacing the racks of electrodes when inspection and correction of the deposit is required. Conventional means, not shown, is provided at opposite ends of the machine for handling the electrodes and loading and unloading the machine. Continuous and automatic removal of the slimes formed during electrolysis is accomplished by means of a slime gathering attachment which is fastened to an electrode rack and passed through the tank.

Copper refining machine construction Referring to the drawings in detail, wherein like reference characters designate similar parts throughout the various views, Figure 1 shows a preferred schematic layout of the tanks and electrical connections for a machine designed to produce electrolytic copper according to our invention. Two rows of tanks made up of three tandem arranged tanks are shown, designated A, B, C and A, B, 0. Any number of rows of tanks can be used as desired. A single tank may be substituted for the three tandem tanks, however, for practical reasons of tank construction, operation and electrical control, a minimum of three tanks is preferred. For elevating the racks of electrodes, as required along the path of travel, to inspect and correct the cathode growth, a traveling crane means generally designated at D is arranged to travel along adjacent or over the tanks. Washing and inspection stations are provided between the tandem arranged tanks as diagrammatically illustrated at E.

Suitably shaped electrodes 25 formed by conventional methods from impure copper are assembled on supporting racks, generally designated 21. The electrodes are uniformly spaced lengthwise thereof, with minimum clearance being provided between the opposed edges of the electrodes supported on adjacent racks. The electrodes are maintained in this fixed spaced relationship, while the racks are moved along from one end of the tank to the other as a unit, at a definite rate of speed, with the electrodes suspended in electrolyte and electrically connected in series with a source of direct current.

Electrical connections made to the tanks are such that the current distribution within: a single tank will be a multiple series combination. A bus bar extends along at opposite sides-of the tank and makesconnection with the end electrode on each of the spaced racks. The totalcurrent from the bus bar isrdistributed to the plurality of racks and conducted to the electrodes by series arrangement. Preferably the current used is on the order of from 5,000 to 12,000 amperesper tank at an average voltage of between 15 and 30. The electrical energy supplied each tank and the rateof travel of the racks are correlated so that electrolysis of the electrodes will have been completed by the time they reach the end of the tank C or C". A typical electrical connection. for two rows of tanks is illustrated diagrammatically in. Figure 1' wherein the bus bars 36 are connected to a direct current generator G by suitable electrical conductor'means as indicated'at 32. One or more generators or other sources of electric current may, of course, be utilized depending upon the size-and number of tanks or electrolytic cells used.

Tank and electrode rack conveyor mechanism Each of the tanks are similarly constructed and, as illustrated in Figures 2, 3, 5 and 14., are formed of concrete or steel 33 which is covered with electrical insulating material which is resistant to electrolytic attack, such as rubber, resin or the like as indicated at'34. The bottom of the tank is shaped to :comprise a fiat or crown surface 36 with side gutters 38 for collecting; the slimes which are swept from the surface portion 36 during electrolysis. Drain openings 40 in the gutters communicate with the drain pipe means 4t.

which are suitably connected to slurry pumps, not shown, whereby the slimes are carried away for treatment. Inlet and outlet pipe connections 42 and 44, respectively, are provided as shown in Figures 5 and 14' for introducing and removing electrolyte. Conventional means, not shown, are also utilized to bring about circulation of the electrolyte and for maintaining it heated to the temperature at'which minimum resistance is of fered to passage of electric current.

The electrodes 25 are hung on the racks 21; as illustratedin Figure 5, and moved edgewise through the tank. Spacing of the electrodes is such as to give the maximum current eflicie'ncy. Due to the precision in mounting and conveying of the electrodes, the space between individual electrodes on each rack can be held'toapproximately one half inch or-less, whereas thespace between the edges-of electrodes on adjacent racks may be on the order of one quarter of an inch Sufiicient space is left below the electrodes to pr vide for attaching a slime collecting rack The continuous movement of the electrodes through the electrolyte effects a. horizontal circulation of the electrolyte in addition to the vertical circus lation between. the electrodes caused by the change in specific gravity of the electrolyte during electrolysis and that brought about by mechanical means.

Suitable mechanism for moving the racks i1 is shown in. Figures 4. and and comprises the screw shafts 50 which are axially spaced to extend along the ledge at opposite sides of the tank. Screw follower means 52,- as shown in Figure 5, is bolted to the outer ends of the racks 21 as indicated at 53, and 'is advanced upon rotation of the screw means. The screw shafts 50 are syn.- chronously drivenby motor 54, as illustrated in Figure 4, which is drivingly connected thereto through a reduction. gear box 56, pinion- 58, gear and worm: driveshaft 62. This latter shaft drives the axially spaced screw'membersby means of the spaced worm sections 63 which mesh with gear means 65 keyed respectively to the screw shaftsill; Journal bearing members 6! are providedv adjacent the ends of the screw shafts and additional bearing means 69 are utilized to support'the screw shafts intermediate the journals. In place of the screw drive mechanism shown, a rack and pinion means may be used to propel the electrode racks where greater tolerances are permissible.

Construction of the racks 21 and the manner of assembling the electrodes 25 thereon are illustrated in Figures 4, 5, 6 and 8. As shown in Figures 6 and 8; the racks comprise spaced channel frame members 1-0- of a length to span the tank, which are tied.- together at intervals by I-shaped web sections l2, the latter being preferably welded to the side walls of the channels as indicated at 14. This provides'a rack which is sturdy and capable of supporting. a group of electrodes without deformation. The depth of the I-shaped web members I2 is such that when welded in place, as illustrated inFigure 6, a space 16 is provided to accommodate the T-shaped hangers, generally designated 80, upon which individual electrodes are removably hung. For interlocking, the hanger-members with the rack, opposed strip means 82 is bolted or otherwise fixed to-the'inside of the channel members III, as shown in Figure 6, forming a ledge for slidably engaging and retaining the ends of the hanger head portion 84-.

Electrode hanger and clamping mechanism Hangers 86, which support electrodes intermediate the ends of the rack, are formed of suitable dielectric material, such as hard rubber, synthetic resin, wood or the like, and shaped as illustrated in Figure 10. Spaced integral pin means 86 are provided on the depending body portion 88 of the hanger for fitting inapertures 9!] of theelectrode, as shown inv Figure 11. The thickness of the body portion 88 of the hanger is preferably about half that of. the head part 84 which is approximately double that of the electrodes. By shaping the hangers in this way the electrodes can be nested together as illustrated in Figure 9 and maintained properly aligned. Further, the hangers which are made of dielectric material operate to accurately space and electrically insulate the electrodes from each other as well as removably support the same on the rack. To prevent contact ofv the electrodes with the underside of the channel members electrical insulating material is interposed therebetween as at 89.

Adjacent the clamping end ofeach rack, as shown at the left in Figure 5, a somewhat differently shaped hanger 94 is used to support the end electrode in order to make. electrical connection with the end. electrode from the busbar 30. This hanger is shaped. to receive a metal insert 96 and is provided with metal hanger pins 98 upon. which the end electrode is supported, as depicted in Figure. 7.

For firmly holding'the group of electrodes together on each rack, suitable clamping means is provided? as illustrated inFigures 4, 12 and 13. In Figure 12' an adjustable clamping, assembly and electrical. connecting means is illustrated and comprises a movable plate I06 having extended slots I66 formed. inthe channel members 10 and-- permit the plate to be moved toward or away from the fixed angle members I by advancing or retracting the nuts I09 on the bolts I00, as illustrated in Figure 4.

Electric current is passed to the end electrode through the member H0 from the bus bar by connection with the integral arm member H2. Arm member H2, as illustrated in Figure 12, is electrically insulated from metal plate I00 by means of the member H5. Preferably the arm member H2 is arranged to pass through apertures in the plate I00 and insulating member H5 as shown in Figures 5 and 12.

At the opposite end of the rack, as shown to the right on Figure 5, the end electrode forming a cathode is preferably made of pure copper, and normally is held at its uppermost portion against the metal plate H8 which plate is bolted to the channels 10 and electrically insulated therefrom, as indicated at H9 in Figure 4. The lectrode hangers are clamped firmly against this fixed end plate by the adjustable plate I00 at the opposite end of the rack. Electric current is conducted from the end electrode to the adjacent bus bar 30 by way of the plate I I8 and electrical conducting arm member I20, as illustrated in Figure 13.

Electrical connection between the bus bars and arm members I I2 and I may be made by sliding contacts but in the preferred embodiment shown the metal bus bars comprise elongated grooves I2I filled with mercury, as illustrated in Figure 5. Arm members H2 and I20 are arranged to extend over the mercury filled grooves I2! and make direct electrical contact with the mercury by means of the depending rod members I22. Slots I24 in the arm members H2 and I20 permit adjustment of the mercury contacting members I22. Suitable electrical cable connection is made to the ends of the bus bars, as shown at I20 in Figure 4, to conduct current to or from the same.

Roller support for electrode racks To support the weight of the racks of electrodes and to provide for their movement therealong as a unit, each rack is equipped with rollers I30, one being arranged at each end. The rollers I30 are supported for movement on rails I32 which are mounted on top of the tank and extend alon in the direction of its length as illustrated in Figures 4 and 5.

Suitable space is provided for accommodating the rail I32, bus bar 30 and associated mechanism at opposite side of the tank beneath the channel member 10 as at I34 by reducing the depth of the channel portions projecting over the side walls of the tank as shown in Figures 5, 14, and 18. The bus bars 30 arrangedat opposite sides of the tank are suitably insulated from the tank a shown at I35 and are secured in position by the insulating spacers I33 which are fastened to the rail I32, as shown in Figure 5.

Rollers I30 are mounted in a U-shaped casting assembly I31 as illustrated in Figures 5 and 8. The casting I31 is bolted to the channel members 10, as shown in Figure 8. The axle shaft of the roller is formed by an extension of the bolt 53 which passes through suitable apertures in the leg members I39. A nut I is threaded on the end of the bolt 53 to hold the parts together. By this construction the entire weight of the rack and electrodes is carried by the rails I32 and no bending stresses are placed upon the screw shaft which would interfere with its; operation.

Lifting lugs I are provided at each end of the racks so that the racks can be readily grasped by means attached to the crane 22 and lifted in and out of the tanks. Preferably the lugs I45 form an integral part of the casting I31 as shown in Figures 6 and 7. The casting is also provided with eyelet lug members I41 which are adapted to be engaged by suitable means on the traveling crane to lock it to the moving racks adjacent to the rack which is to be lifted out of the tank. In this way racks which are raised out of the tank continue to travel with the remaining electrodes whereby their relative position in the direction of travel is retained.

Slime rack mechanism For efiecting removal of the slimes which form during electrolysis and settle down on the bottom of the tank, a slime collecting means, such as illustrated in Figures 14, 15, 16 and 17 is utilized. This mechanism consists of a rectangular shaped frame means carrying plow blades and is adapted to be attached to an electrode rack and moved through the tank. In the embodiment shown, upright frame members I50 are rigidly attached at the top to the outer ends of an electrode rack and at their lower ends to the spaced interconnecting frame members I52. On the underside of the members I52 are mounted the plows I54 which are equipped with soft rubber wiper blade means I56 as illustrated in Figures 15 and 16. The end blade on opposite sides of the rack extends over the gutter 38 and comprises a depending blade portion I58 which engages therein. A central support for the blade rack may be provided where the width of the tank necessitates it. Such a support is illustrated in Figure 14, and consists of one or more tie rod members I50 which are attached at the bottom to the plate I82 and fastened at the top to the racks as shown at I64. To provide space for the central support I60 one electrode is omitted from the center of the rack. All parts of the slime collecting member which come in contact with electrolyte are protected by rubber or the like covering as indicated at I66. Movement of the slime collecting means through the tank operates to sweep the settled slimes from the surfaces 36 and 38 into drain openings 40 where they are carried off through the pipes M by means of a slurry pump, not shown.

Mechanism for handling the electroderacks For removing the racks of electrodes from the electrolytic tanks, as required at intervals, a travelingcrane such as illustrated in Figures 18, 19, and 20 is provided. The mechanism preferably is of the electric traveling crane type comprising suitable structural frame means I12 upon which is mounted spaced hydraulic cylinder lifting means I 14, as illustrated in Figure 18. As shown, the crane is supported and arranged to travel on the rails I16 which extend along at opposite sides of the tank. T0 propel the crane, electric motor means I18 is geared to drive one of the pair of wheels I provided at opposite sides of the crane. Dual motor drive means is preferably used to produce a balanced, smoothly operating mechanism. Electrical energy is supplied to the crane operation motors through suitable overhead or side trolle wire connections as illustrated t I82 on Figure 19.

The hydraulic cylinders I14 on the crane 22 are operatively connected to the opposite ends of the beam I85 to the vertically reciprocable piston means I86. Beam I85 is supported for movement between the end frame columns I88 and overhead gag-moobridge. structure 090. To guide the movement of the elevating beam [85 suitable rack and pinion means I92 and I94 respectively are provided. as shown in Figures 18 and 19. Pivoted hooks 200 carried by the reciprocable beam I85 are spaced to engage the pins 202 of the lugs I45 fastened at the opposite ends of the electrode racks. The hooks 200 are operatively connected tothe lifting pins 202 when they are swung from the dotted line position depicted in Figure 18 to the full line position. Mechanical leverage means is employed to control the position of the hooks. Suitable mechanism for accomplishing this is shown in Figure 1-8 wherein adjustable link means 206 is arranged to swing the hooks 200 in and out of engagement with the pins 202. The link members 206 are secured at their opposite ends to a lever 208 which is pivoted intermediate its ends as at 209-. Movement of the lever about its pivot is effected by means of a hydraulically operated piston and cylinder means 2 I which is mechanically connected to the lever 208 by means of the piston rod 2I2' and link 2 I4. It will thus be seen that reciprocation of the piston rod 2I2 and connecting link 2I4 shifts the lever 208 about its pivot to swing the hooks 200 inward or outward as desired;

The hooks and operating mechanism including the piston cylinder 2 I 0 is mounted on the movable beam- I85. Flexible conduit means 2 I 5 is used to connect the cylinder 2 I0 to the central controlled valve 2I 8- which is positioned adjacent the operators station on the platform 220, as illustrated in Figure 20. Fluid-like pressure is supplied from a suitable source, not shown, and is connected to the valve 2I-8. Hydraulic pipe connections 222 and 223' are connected to the hydraulic cylinders I'M-which raise and lower the beam I85.

To interlock the traveling crane 22 with the moving electrodes when it is desired to elevate a particular rack of electrodes out of the tank, rocker shaft means 221 is mounted on opposite sides of'thecrane adjacent the ends of the racks assho'wnin Figure 20. Arm members 229 are attached tothe rocker shafts and are spaced so that their respective end lug or hook portions 230 will engage in the eyelets I41, when the rocker shaft is actuated to swing the arms downwardly from a raised position, a illustrated in Figure 18. Each pair of arm members 229 are arranged to interlock with the eyelets I 4'! on spaced racks, as shown in Figure 20, whereby the intermediate rack is free to be raised out of the tank for inspection and adjustment and lowered back in its place while the crane and racks of electrodes move along asa unit. Each of the rocker shafts pure copper, which are to be bipolar arecoated onthe cathode face, inthe conventional manner, toperm-i't the copper deposit to be readily stripped from-the unrefined portion atthe end of the process: The electrodes are assembled onthe racks in spaced, electrically insulated arrangement bea predeter l ined dist'ance. means onasaidi rack for clamping: sa hangers together to formacomtween anode and cathode electrodes as hereinbefore described, and positioned in. the tanks filled with electrolyte. Electrical current connections are made to the racks as described and the screw drive conveyor operated to move the electrodes along through the solution from one end of thet'ank to theother. During this movement the electrolyte, which is heated to a high temperature, is circulated through the tanks. During normal operation, the tanks are kept full of electrodes. When a rack of electrodes is removedfrom one end of a tank, another rack is introduced at the other end to provide a continuous electrolytic process.

The electrodes intermediate the end electrodes on the racksare bipolar. Impure metal, on the side from which the currentleaves, is dissolved while pure copper is deposited on the other side. As" the electrolysis proceeds-and the electrodes are conveyed through the three tanks intandem, the electrolyte level in each tank is adjusted to leave a certain portion unrefined as a support for the newly deposited metal.

Slime's which gradually accumulate on the bottom of the tan-hare continuously swept into the gutters provided to-receive the same by a slime gathering means: which issuitably fastened to an electrode rackand-moved through the tank. The

electrodes are continuously advanced from the the end electrodes constituting the anode and cathode remainstationary. this alternative construction the electrioal connections to the anode and-cathodeelectrbdes' H'iay-be of the (501ivel iti'onal typeplace of the mercury type shown.

It will be unclersteod thatwe desire to comprehend invention Such ofil' ll 0153123865 and modifications as may readily suggest themselves 'tothose skilled the art and which-come withih the scope of the: appended claims! W claim:-

1. amachineror use tn zprodiictionof electrolytic-copper which comprises a tank for holdin'g' copper electrolyte solution racks arranged crosswise or said tank at spaced intervals throughout the length: of: said tank, hangers disposed on said rack for supporting electrodes, s'afd electrodes being formed of impure copper and suspendedifrom said hangers: whi'cltanez' carried leyvtheraeks said: hangers comprising an: accurately-"shaped -portion formed": of dielectric manner which abuts against the adjacent hanger" f-rcm which an electrode is: suspended when the hangers and attached electrodes are compacted on a rack retainingthei electrodes fixedly and accurately spaced from eachother pact g roup conveyor means comprising. a pair" of axially-'- spaced: screw members: which are s nin chrcnously' driven; screw followers attached at the opposite ends of each rack operatively connected to said screw members, a motor and associated gear reducing means for synchronously driving said screw members to advance said racks as a unit in a continuous manner from one end of said tank to the other, means for electrically connecting the first and last electrodes on each rack of electrodes to a source of direct electric current and passing electric current to said first electrode and through the electrolyte to each electrode in series to said last electrode on the rack continuously as said racks of electrodes are moved along through the electrolyte to cause electrolysis to take place and the electrodes between the first and last on each rack to become bi-polar electrodes with the surface facing toward said first electrode being cathodic and the opposite surface facing toward said last electrode being anodic and causing said bi-polar electrodes to corrode away and the copper to pass into solution in the electrolyte and be electrodeposited out on the cathode surface of the adjacent electrode.

2. An electrolytic machine for refining impure metal electrodes by electrolysis comprising a tank for holding electrolyte, a rack spanning said tank, metal electrodes to be electrolytically refined spacedly supported on said rack and arranged for suspension in the electrolyte in the tank, said rack comprising an anode and cathode with intermediately spaced electrodes of impure metal, means for electrically connecting the anode and cathode electrodes on said rack to a source of direct electric current and passing electric current to the anode and through the electrolyte to each of the spaced intermediate electrodes solely through the electrolyte in series to said cathode, means for moving said rack of electrodes as a unit from one end of said tank to the other, and means for conducting electric current to the electrodes on the rack continuously as the same is moved from one end of the tank to the other.

3. An electrolytic machine for refining impure metal electrodes by electrolysis comprising a tank for holding electrolyte, a plurality of racks spanning said tank, each of said racks comprising an anode and a cathode with intermediately spaced electrodes of impure metal to be refined spacedly supported on the rack and arranged for suspension in electrolyte in the tank, means for electrically connecting the anode and cathode electrodes on the respective racks to a source of direct electric current and for passing electric current from the anode and through the electrolyte to each of the spaced intermediate electrodes on a rack solely through the electrolyte in series to the cathode, means for moving said racks of electrodes as units from one end of said tank to the other, means for conducting electric current to the electrodes on the racks continuously as same are moved from one end of the tank to the other, and crane means operatively associated with said rack moving mechanism for elevating and lowering a selected rack of electrodes while maintaining its relative horizontal spacing between adjacent racks and while continuing the movement of the racks of electrodes from one end of the tank toward the other. 7 t

4. An electrolytic machine for refining impure metal electrodes by electrolysis comprising a tank for holding electrolyte, a plurality of spaced racks spanning said tank, metal electrodeseto be electrolytically refined spacedly supported on said racks and suspended in the electrolyte contained in the tank, each of said rack of electrodes comvto the electrodes on the rack continuously same is moved along in said tank.

prising anode and cathode electrodes with intermediately spaced electrodes of impure metal all carried by said rack and arranged for suspension in electrolyte in the tank, means for electrically connecting the anode and cathode electrodes on said racks to a source of direct electric current and passing electric current from anode to electrolyte and to each of the spaced intermediate electrodes on each rack solely through the electrolyte in series to the cathode,means for moving said plurality of spaced racks of electrodes as a unit from one end of said tank to the other, and means for conducting electric current to the electrodes on the racks continuously as the same are moved along from one end of the tank to the other.

5. An electrolytic machine for refining impure copper electrodes by electrolysis comprising a tank for holding electrolyte, a rack spanning said tank, anode and cathode electrodes with intermediately spaced electrodes of impure copper to be electrolytically refined supported on said rack, said electrodes being arranged for suspension in electrolyte in the tank, means for electrically connecting the anode and cathode electrodes on said rack to a source of direct electric current and for passing electric current from anode to the intermediately spaced impure copper electrode means and thence to cathode solely through the electrolyte in series, means for moving said rack of electrodes as a unit from a loading to an unloading station in said tank, and means for conducting electric current to the electrodes on the rack continuously as the same is moved along through said tank.

6. An electrolytic machine for refining impure copper electrodes by electrolysis comprising a tank for holding electrolyte, a rack spanning said tank, anode and cathode electrodes with intermediately spaced electrodes of impure copper to be electrolytically refined supported on said rack, said electrodes being arranged for suspension in electrolyte in the tank, means for electrically connecting the anode and cathode electrodes on said rack to a source of direct electric current and passing electric current to the anode through the electrolyte to the intermediately spaced impure copper electrode means solely through the electrolyte in series to the cathode, means comprising a pair of screw shaftsoperatively connected to the opposite ends of said rack for moving said rack of electrodes as a unit from a loading to an unloading station in said tank, means for synchronously driving said screw shafts, andmeans for conducting electric current as the 7. An electrolytic machine for refining impure copper electrodes by electrolysis comprising a tank for holding electrolyte, a rack spanning said tank, anode and cathode electrodes with intermediately spaced and electrically insulated electrodes of impure copper supported on said rack and arranged for suspension in electrolyte in the tank, means for electrically connecting the anode and cathode electrodes on said rack to a source of direct electric current and passing electric current from the anode through the electrolyte to the intermediately spaced electrodes solely through the electrolyte in series tothe cathode,

means for moving said rack of electrodes as a unit from one end of the tank to the other, slime ,for removing the slimes produced during electrolysis, and means for conducting electric current to the electrodes on the rack continuously as the same is moved from one end of the tank to the other.

8. An electrolytic machine for producing electrolytic copper by electrolysis comprising a tank for holding copper sulphate electrolyte solution, a rack spanning said tank, anode and cathode electrodes with intermediately spaced electrodes of impure copper carried by said rack and arranged for suspension in the electrolyte in the tank, scraper means positioned in said tank engageable with the bottom of said tank and operable to move the slimes which gradually accumulate on the bottom of the tank during electrolysis into drain means in said tank for removal, means for electrically connecting the anode and cathode electrodes on said rack to a source of direct electric current and passing current to the spaced impure copper electrodes solely through the electrolyte in series to cathode electrode, means for moving the rack of electrodes and slimes scraper as a unit from one end of the tank to the other and means for maintaining the electrodes connected to said direct current source While said rack of electrodes is being moved along from one end of the tank to the other.

9. The process of electrolytically refining copper by electrolysis which consists in suspending anode and cathode electrodes with intermediately spaced electrodes of impure copper in copper sulphate electrolyte solution, maintaining said electrodes accurately spaced and electrically insulated from each other except through the electrolyte, passing direct electric current to the anode electrode and to said intermediately spaced impure copper electrodes in series to the cathode, moving all of said electrodes as a unit along through the electrolyte from a loading to an unloading station, continuously circulating fresh electrolyte about said electrodes and withdrawing the slimes formed during electrolysis simultaneously as the electrodes are moved along and the electrolysi proceeds, said electrolysis being continued during movement of the electrodes until the impure copper electrodes have been substantially replaced by electrolytic copper.

10. In the process of electrolytically refining copper by the series system using anode and cathode electrodes with intermediately spaced electrodes of impure copper, the step of continuously moving the electrodes through the elec- 14 trolyte from one end of the electrolytic cell to the other while simultaneously effecting electrolysis of the impure copper electrodes by passing electric current from the anode to the impure copper electrodes solely through the electrolyte in series tot he cathode.

11. In the process of electrolytically refining copper by the series system wherein anode and cathode electrodes together with intermediately spaced electrodes of impure copper are placed in electrolyte and subjected to electrolysis, the steps comprising supporting and moving all the electrodes as a unit through the electrolyte, circulating electrolyte between the electrodes and concurrently removing the slimes formed during electrolysis as the electrodes are moved along through the electrolyte and subjected to electrolysis.

12. In an electrolytic cell for effecting series electrolysis to refine metals, the combination of an electrolytic cell for depositing metal, an anode, a cathode, intermediate bipolar electrodes formed of impure metal to be refined, means arranged over said cell for suspension of the electrodes in the electrolyte contained in said cell, hangers on said suspension means for independently supporting the electrodes in spaced relationship and electrically insulated from each other except through the electrolyte, means for connecting the electrodes in series with a direct current source of electricity to cause electrolysis to take place and the bi-polar electrodes to corrode away and the metal to go into solution in the electrolyte and electroplate onto the cathode surface of the next adjacent electrode, and means for moving the bipolar electrodes horizontally through the cell as electrolysis proceeds.

KARL A. LINDNER. WILLIAM M. MORRISON. ADOLPI-I BUSCHE.

REFERENiDES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 485,618 Farrel Nov. 8, 1892 587,782 Bossard Aug. 10, 1897 1,187,903 Greenawalt June 20, 1916 2,030,984 Hannon Feb. 18, 1936 521,991 Sachs June 26, 1894 2,312,452 Taylerson Mar. 2, 1943 

